Index advice is malformed - LET, ISMISSING, parenthesis, multiple index names

Summary: When entering a query that has a relatively complex LET, the index recommendation is malformed.

Repro:

1. In query workbench, enter a query like below
2. Click "Advice"
3. Observe the index recommendation

Actual:

Index recommendation is:

(I attached as screenshot and a text file since Jira keeps mangling the formatting because of the backticks)

When trying to execute that recommendation, there is a syntax error.

Expected:

No syntax error, index executes correctly. It appears there are multiple issues with this index, including multiple names separated by commas, and some parenthesis misplacement (at least).

Notes:

The query:

select p.file.fullName, score
from familyPhotos p
let score = IFMISSING(p.ranking.scores.emma,0) + IFMISSING(p.ranking.scores.matt,0) + IFMISSING(p.ranking.scores.ali,0) + IFMISSING(p.ranking.scores.matthew,0)
where score > 0
order by score asc, p.file.fullName asc LIMIT 50;